Rooting rose bush cuttings is relatively easy, provided you take cuttings with a sharp cutting tool that doesn't crush the stem. For most roses, the best time to take cuttings is November through February, although success can be achieved at almost any time of the year. While it is possible to plant cuttings directly in the garden, rooting cuttings indoors in a pot with a makeshift "greenhouse" gives you the ability to better control the process.
Cut one or more stems (new growth), making the cut with a sharp blade just below a leaf node. Stems should be about 6 to 8 inches long and the cut should be made at a 45-degree angle. The best stem candidates for cuttings are tips of branches that have recently bloomed.
Remove the leaves on the lower half of the cut end of the cutting. Leave the leaves at the upper end.
Dip the cut end of the cutting into powdered growth hormone, which is available at any nursery and many retailers. Knock off excess growth powder.
Fill the pots with a mixture of approximately two-thirds sand and one-third peat moss, well mixed.
Make a hole in the potting mix using a pencil or similar object. Insert about half of the cutting into the soil. Tamp the soil around the cutting until it is firm. If planting multiple cuttings in the same container, plant cuttings 6 to 8 inches apart. Water until the soil is damp.
Cover the pot with a plastic bag and secure around the pot to form a make-shift greenhouse. You can also use a washed plastic 2-liter soda bottle for this. If you choose this option, cut the bottom end off and place the spout end of the bottle over the cutting, creating a mini greenhouse with an open "chimney" at the top for air circulation.
Place the pot in a warm location where it gets 4 to 6 hours of indirect light each day.
Remove the soda bottle or plastic bag occasionally to prevent the constant dampness from causing the cuttings to rot. Make sure the soil stays damp, but not overly wet. Watch for new leaf growth, which should begin in 4 to 8 weeks. At the first sign of new leaf growth remove the soda bottle and allow the rose to have at least an hour or two of direct sunlight a day.
Wait until the following fall to transplant cuttings to the garden. By that time, the root system will have developed enough to survive transplanting.